The present invention relates to fault indicators of the type which respond to an abnormally high electric current, in a conductor, cable, busbar, power line, etc.
Fault indicators of the type to which the invention pertains are known in at least one configuration based on the principle of inductive current sensing in a conductor. For example, U.S. Pat. No. 3,895,296, discloses a fault indicator which is in some fashion suspended on a cable and includes a current transformer whose sensing winding controls an indicator. The current in that sensing winding is also used to reset the indicator. A current transformer to be used in conjunction with such a fault indicator is shown, for example, in U.S. Pat. No. 3,962,661. Installation of such a transformer, particularly looping it around the cable, is rather difficult. Also, the surfaces exposed upon separation of the core parts are prone to accumulate dirt which may change the response for triggering as well as for resetting.